Hi folks,

I'm curious. I have a pair of box-jointed pliers made by CK. If I was to
remove the pin from the joint in the pliers, the joint still wouldn't
come apart because the shape of the two halves of the joint holds it
tightly together. I can only assume that the two halves start out as
three forged components, which are then ground and assembled, and lastly
a permanent joint is made somewhere by hot forging or resistance
welding. But the joint isn't visible at all. I've seen a similar joint
in some monkey wrenches, but it's not so intriguing as the monkey wrench
can still be taken apart.

Does anyone know how this is achieved?

Best wishes,

Chris

Not quite. They forge both parts to roughly the finished shape. Then
reheat the part that has the box, open the box up enough to insert the
other half through the hole, then, after positioning the halves in the
correct position, forge the parts together. Since this is done below a
welding heat, no bond forms. One reheats the whole thing and forges
the assembly to final shape. Then, the hole is drilled for the pin.
The pin is riveted into place. Then it's file or grind until done.
Pete Ross, previous master blacksmith and manager of the
Williamsburg blacksmith shop for many years makes them often. He says
you only need to make about 25 pairs of box tongs to get good at it.
I bought a completed pair, a pair that are ready to rivet and the
two blanks needed to make another pair at a blacksmith auction in
Asheville, NC some years ago. I had watched him make them.

Pete Stanaitis
----------------------

Christopher Tidy wrote:
Hi folks,

I'm curious. I have a pair of box-jointed pliers made by CK. If I was to
remove the pin from the joint in the pliers, the joint still wouldn't
come apart because the shape of the two halves of the joint holds it
tightly together. I can only assume that the two halves start out as
three forged components, which are then ground and assembled, and lastly
a permanent joint is made somewhere by hot forging or resistance
welding. But the joint isn't visible at all. I've seen a similar joint
in some monkey wrenches, but it's not so intriguing as the monkey wrench
can still be taken apart.

Does anyone know how this is achieved?

Best wishes,

Chris

spaco wrote:
Not quite. They forge both parts to roughly the finished shape. Then
reheat the part that has the box, open the box up enough to insert the
other half through the hole, then, after positioning the halves in the
correct position, forge the parts together. Since this is done below a
welding heat, no bond forms. One reheats the whole thing and forges
the assembly to final shape. Then, the hole is drilled for the pin.
The pin is riveted into place. Then it's file or grind until done.
Pete Ross, previous master blacksmith and manager of the Williamsburg
blacksmith shop for many years makes them often. He says you only need
to make about 25 pairs of box tongs to get good at it.
I bought a completed pair, a pair that are ready to rivet and the
two blanks needed to make another pair at a blacksmith auction in
Asheville, NC some years ago. I had watched him make them.

Thanks, Pete. That was a fascinating explanation. It explains why I
can't see a join in my pliers.

I assume CK have a production line set up which forges the outer part of
the box joint complete with the pre-expanded slot, but I'm just guessing
here. My pliers are CK No. 3772 if anyone else has a pair they'd like to
inspect.

Now there is such a thing as forge welding, isn't there? The monkey
wrenches I'm thinking of are "Trimo" brand. They have a channel which is
box-shaped in cross-section. I've seen one with a crack along the centre
of the channel from overloading. Whether these were forged solid and
later had the channel milled out, or whether the channel was forge
welded, I don't know. Anyone know for sure?

I don't own one, but I'm tempted to buy one now just so that I can
inspect it.

Best wishes,

Chris

Yes, I suppose the box half could have been made in two pieces, forge
welded together after being closed around the other half. But forge
welds are generally considered not quite as strong as the parent metal.
And, although the idea of drifting the square hole open to round
after initial forming may sound foriegn to non-blacksmiths, we get used
to extreme hot forming and shape change.

Pete Stanaitis
---------------------



Now there is such a thing as forge welding, isn't there? The monkey
wrenches I'm thinking of are "Trimo" brand. They have a channel which is
box-shaped in cross-section. I've seen one with a crack along the centre
of the channel from overloading. Whether these were forged solid and
later had the channel milled out, or whether the channel was forge
welded, I don't know. Anyone know for sure?

I don't own one, but I'm tempted to buy one now just so that I can
inspect it.

Best wishes,

Chris

spaco wrote:
Yes, I suppose the box half could have been made in two pieces, forge
welded together after being closed around the other half. But forge
welds are generally considered not quite as strong as the parent metal.
And, although the idea of drifting the square hole open to round
after initial forming may sound foriegn to non-blacksmiths, we get used
to extreme hot forming and shape change.

How precise are your pliers, Pete? The ones I have are really tight; you
couldn't get a hair into the joint. If you can make a joint that tight
by forging, that's amazing.

Best wishes,

Chris

On Thu, 20 Dec 2007 15:17:54 -0600, spaco
wrote:

Pete Ross, previous master blacksmith and manager of the
Williamsburg blacksmith shop for many years makes them often.

Ever seen the video of Peter Ross making a reproduction andiron? I'm
not sure whether it's inspiring or discouraging to see him do in 30
minutes what I'd be delighted to accomplish in 4 hours.

--
Ned Simmons